How a battery earns · NPV / IRR / payback per market · $/MWh-delivered (LCOS) vs LFP · target-market prioritisation
How a battery earns — revenue streams & where WiS bids
A grid battery earns from up to four stacked sources: energy arbitrage (buy cheap, sell peak),
balancing services (paid for standing ready to stabilise the grid), capacity contracts
(paid for guaranteed availability, often 15-yr), and behind-the-meter savings (cutting a factory's peak
demand charges). Response time decides who can bid: sub-second products (FCR, FFR, RegD) are Li-ion
territory and we don't chase them; the 5–15-minute products and capacity contracts are where the aqueous battery earns.
Figures: annual revenue per 1 MW at 80% capture, 2024 prices.
Revenue stream
What it is
Response required
2024 price
Revenue / MW·yr
WiS fit
Same 1 MW battery, four strategies — stacking transforms the economics (annual revenue, k)
Where it earns best: US ERCOT ECRS — payback 2.8 yr (highest-margin WiS-fit product).
Best in EU: Germany aFRR + arbitrage — 3.1 yr. Most bankable: Polish capacity market —
a 15-year indexed contract covers the majority of revenue with an investment-grade counterparty,
which is what project financiers underwrite. Full NPV / IRR / payback per market in the table below.
Base case: 1 MW / 1 MWh · 20 years · WACC 8% · CAPEX ~$250/kWh (conservative near-term basis — the at-scale
target is $120/kWh, so every payback below has headroom). Revenue = stacked strategy realistically available
to a 5-min-class aqueous battery. Sizing note: WiS systems are power/energy-decoupled — slow ~8 h charge,
fast discharge, so power:capacity is never a fixed 1:1; the 1 MW / 1 MWh base case is kept only for like-for-like
comparison with Li-ion benchmarks. Duration-heavy WiS variants get cheaper per kWh, because the stack is sized by
discharge power and extra energy is marginal electrolyte. * AU / NY rows use the interactive calculator further
down the page (20-yr horizon, preset system sizes). The revenue-stream table above shows each product's
ceiling at 80% capture; this model applies realistic capture, derating and competition per market — hence
lower figures for the same product.
Market
Strategy (WiS-fit stack)
Annual rev
CAPEX
NPV (20 yr)
IRR
Payback
Fit
Payback by market — WiS-fit stacked strategies (years)
Why revenue stacking favours WiS — the cycle budget.
Stacked merchant operation (arbitrage + aFRR/ECRS + capacity obligations) runs ~1.5–2 equivalent cycles/day
≈ 11,000–14,600 cycles over 20 years. That sits inside the WiS design budget (12,000–25,000) but is ~2× LFP's
6,000–8,000 — at stacked duty LFP needs a full mid-life replacement every ~9–14 years, which the LCOS table
above prices in and which stacking economics rarely survive. The strategies marked reference are shown
for honesty: FCR / FFR products (<30 s / <250 ms response) are Li-ion territory and we do not bid there;
our stack lives in the 5–15-minute products (aFRR, mFRR, ECRS) and capacity contracts, where response time
does not disqualify the static aqueous battery and where cycle budget decides the 20-year economics.
Max viable CAPEX per strategy (IRR ≥ 15%)
The CAPEX ceiling at which each strategy still clears a 15% IRR — read against the WiS cost ladder
(today ~$450/kWh low-volume lab · Stage B pilot ~$300 · at-scale target $120; see Financials).
Size a system, pick a market, and compare how much each storage technology earns — net revenue, payback, NPV and LCOS. Tick which technologies to compare; every parameter is editable. Power and energy are decoupled: you sell the discharge power; charging is deliberately slow.
The WiS design asymmetry is ~5×: a 1 MWh unit charges at ~100 kW (≈10 h) and discharges at up to ~500 kW —
slow charge costs nothing, since charge and discharge use the same cell area, and the stack is sized by discharge.
Keep charge time ≥ discharge duration to stay WiS-representative; the model warns if charging would need more power than discharging.
Compare
Technology
CAPEX $/kWh
RTE %
Cycle life
DoD %
OPEX $/kWh-yr
Deg %/yr
Cumulative net cashflow ($)
NPV by technology ($, chosen horizon)
Technology
Net revenue / yr
Payback
NPV (horizon)
LCOS $/MWh
Replacements
20-Year LCOS — $/MWh delivered vs LFP
Cost component ($/MWh unless noted)
LFP · China turnkey
LFP · EU/US installed (non-China)
WiS · 10h (LDES)
Total LCOS ($/MWh delivered)
Honest read of this table: China-turnkey LFP is — and will remain — cheaper upfront, and wins
generic grid-charged LCOS ($76 vs our $88). We don't pitch against that. The WiS case is the buyer who
can't or won't buy China supply (EU/US tariffs, IRA domestic content, CRMA — there we win outright:
$88 vs $101 grid-charged, $42 vs $68 free-charge), plus free/curtailed charging, >6–8 h duration,
high cycle duty (stacking exhausts LFP's 6–8k-cycle budget mid-life) and safety-constrained siting
(indoor, urban, insurance). Note on $/kWh pricing: WiS pricing is duration-dependent — the stack scales
with discharge power, the electrolyte with energy, so the quoted $120/kWh assumes ~10 h; longer duration gets
cheaper per kWh while Li-ion's $/kWh stays flat. Slow ~8 h charging needs no extra stack — charge and discharge
use the same cell area, and the fast-discharge asymmetry is a design feature, not a cost adder.
How we defend a lower RTE and a higher price per kWh — the arithmetic, not a slogan.
Our RTE penalty is a linear function of the charging price: LCOSWiS = $42 + p÷0.65 vs
LCOSLFP·EU/US = $68 + p÷0.9. The $26 hardware advantage (no augmentation, 100% DoD, no membrane)
shrinks by $0.43 for every $1/MWh of charging price — break-even at ≈$61/MWh:
charge @ $0 → WiS $42 vs $68 (−$26) ·
@ $15 → $65 vs $85 (−$20) ·
@ $30 → $88 vs $101 (−$13) ·
@ $45 → $111 vs $118 (−$7) ·
@ $61 → parity
And LDES duty by construction charges in the cheap trough: the slow ~8–10 h charge sits exactly
across the midday solar/overnight wind window ($0–30/MWh, often negative — DE curtails ~19 TWh/yr), because the
asymmetric design sizes the stack by discharge power (what you sell), not charge power. Slow charging
costs nothing in hardware — and behind the meter it cuts the import-power peak (0.4 MW over 10 h instead of
2 MW over 2 h), which directly reduces demand charges. High RTE matters when you buy expensive energy fast;
our segments don't.
Why cycle life = profitability — hardware CAPEX per MWh delivered over life ($/MWh)
The cheapest battery per kWh installed is not the cheapest per kWh delivered.
Cycle life divides CAPEX: every extra cycle spreads the same hardware over more energy sold. At its design budget
WiS hardware costs $5–10 per MWh delivered over life — below even China-turnkey LFP ($11–19), and
3–4× below EU/US-installed LFP ($21–37) — despite a higher price per kWh installed. This is the engine of the
payback numbers above: the more cycles a strategy demands (stacking, daily peak-shaving), the wider this gap gets,
because LFP's 6–8k budget runs out and forces replacement while WiS keeps amortising the same stack.
No storage chemistry wins everywhere. This is the map an investor's own diligence would produce —
we show it first: where WiS wins, where the fight is winnable, and where we deliberately don't bid.
Scenario
Winner
Runner-up
WiS verdict
Why
How storage earns — economics & payback by use-case
Business models — how storage is sold, and where WiS enters vs LFP
Revenue streams say what a battery earns; the business model says who owns the asset, who carries the
technology risk, and how we get paid. A new chemistry cannot enter where LFP is already bankable —
it enters through models that monetise WiS's two structural edges: the cycle budget
(12–25k design vs LFP's 6–8k — service and tolling contracts can cycle hard without warranty pain) and
zero-fire siting (indoor / urban / insurance — where LFP is excluded by fire code).
Business model
How it earns
Who carries technology risk
WiS fit — why
How LFP plays it
Role
Sequencing: Stage B pilots sell as shared savings / storage-as-a-service
(client pays nothing upfront — the only honest offer for a pre-bankable chemistry, and it prices in our
siting advantage). First scale project (2027–28) is a Polish capacity-market SPV — a 15-yr
indexed contract with PSE underwrites project debt, so the technology proves itself on infrastructure-grade
revenue. Direct system sales open after certification + fleet data (Series A), and
licensing stays a Series B+ option for markets we won't enter directly. We never fight LFP
where it is already cheap and bankable — we let the cycle budget and fire-safety premium pay for the entry.
Source model: internal "Aqueous Flow Battery Market Analysis" + 8-market BESS profitability model (real DE balancing data regelleistung.net 2021–25 · Energy-Charts/Fraunhofer ISE · Modo Energy · ERCOT SoM 2024 · Wood Mackenzie / BloombergNEF · Dentons "BESS in Poland" 2025) + market-readiness audit. Figures are directional and tunable — raw model, Python simulations & sources under NDA. ·
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